import java.util.Arrays;

/**
 * @Classname FibonacciSearch 斐波那契查找  黄金分割法
 * @Description TODO
 * @Date 2021/11/24 10:30
 * @Created K024851
 */
public class FibonacciSearch {

    public static int maxSize = 20;

    public static void main(String[] args) {
        int[] arr = {1, 8, 89, 1000, 1234};

    }

    //1、获取斐波那契数列
    public static int[] fib(){

        int[] f = new int[maxSize];

        f[0] = 1;
        f[1] = 1;
        for (int i=2;i<maxSize;i++){
            f[i] = f[i-1]+f[i-2];
        }
        return f;
    }
    //2、编写斐波那契算法

    public  static int fibSearch(int[]a,int key){
        int low = 0;
        int high = a.length-1;
        int k = 0;//表示斐波那契分割数的下标
        int mid = 0;
        int f[] = fib();
        while (high>f[k]-1){
            k++;
        }
        int[] temp = Arrays.copyOf(a,f[k]);
        for (int i=high+1;i<temp.length;i++){
            temp[i] = a[high];
        }
        while (low<=high){
            mid = low +f[k-1]-1;
            if (key< temp[mid]){
                high = mid-1;
                k--;
            }else if( key > temp[mid]){
                low = mid+1;
                k-=2;
            }else {
                if (mid <= high){
                    return mid;
                }else {
                    return high;
                }
            }
        }
        return -1;
    }
}
